The key difference between lytic and lysogenic cycle of bacteriophage is that during lytic cycle of bacteriophage reproduction, the bacteriophage that enters the host cell present as a separate component without integrating with the host DNA while in lysogenic cycle the bacteriophage DNA is integrated into the host DNA and replicate accordingly.
A bacteriophage is a virus that infects bacteria. The reproduction of bacteriophage takes place under two mechanisms (cycles); lytic cycle and lysogenic cycle.
CONTENTS
1. Overview and Key Difference
2. What is Lytic Cycle of Bacteriophage
3. What is Lysogenic Cycle of Bacteriophage
4. Similarities Between Lytic and Lysogenic Cycle of Bacteriophage
5. Side by Side Comparison – Lytic vs Lysogenic Cycle of Bacteriophage in Tabular Form
6. Summary
What is Lytic Cycle of Bacteriophage?
The lytic cycle defines as one of the two reproductive cycles of bacteriophage that involves the destruction of the membranes and the rest of the cellular structure of infected cells. Lytic cycle is mainly shown by virulent pahges.
Bacteriophage DNA
During lytic cycle, the bacteriophage DNA remains as a separate body inside the infected bacterial cell. Therefore, the replication of bacteriophage DNA occurs independently without the influence of bacterial DNA replication.
Influence
The major influence caused by the lytic cycle is the destruction of the membranes of the infected cell. Cellular membrane destruction finally destroys the whole bacterial cell.
Figure 01: Lytic Cycle of Bacteriophage
Stages
The lytic cycle is composed of six different stages. These include an attachment (attachment of the bacteriophage to the bacterial cell surface), penetration (release of bacteriophage DNA), Biosynthesis (DNA replication and the formation of phage proteins), maturation (assembling of newly formed phage particles), lysis (cell lysis takes place) and release of newly formed phages.
What is a Lysogenic Cycle of Bacteriophage?
Lysogenic cycle is one of the two reproductive cycles of bacteriophage that initiates the integration of bacteriophage nucleic acid into the genome of the host bacterium.
Influence
During such phenomenon, the bacterium normally reproduces without the interference of bacteriophage genetic material.
Genetic Material
Prophage is the genetic material of bacteriophage. This prophage transmits to each daughter cell at each level of cell division. The integration of bacteriophage nucleic acid could also occur with the formation of circular replicons on the cytoplasm of bacteria.
Figure 02: Lysogenic Cycle of Bacteriophage
Eukaryotes
It was found out that the functioning of a lysogenic cycle could also take place in eukaryotes. But this concept is not understood fully and need more research.
What are the Similarities Between Lytic and Lysogenic Cycle of Bacteriophage?
- Both processes involve in bacteriophage reproduction.
- Both lytic and lysogenic cycles involve in releasing phage DNA into the bacterial cell.
- Replication of bacteriophage DNA takes place inside the host cell during both cycles.
What is the Difference Between Lytic and Lysogenic Cycle of Bacteriophage?
Lytic vs Lysogenic Cycle of Bacteriophage |
|
| Lytic cycle is one of the two reproductive cycles of bacteriophage that involves the destruction of the membranes and the rest of the cellular structure of infected cells. | Lysogenic cycle is one of the two reproductive cycles of bacteriophage that integrates the bacteriophage nucleic acid into the genome of the host bacterium. |
| Bacteriophage DNA | |
| Occur as an independent unit during the lytic cycle. | Get integrated into the host DNA during the lysogenic cycle. |
| DNA Replication | |
| Bacteriophage DNA replication occurs independently in lytic cycle. | Bacteriophage DNA replication occurs with the bacterial DNA replication machinery in lysogenic cycle. |
| Cell Lysis | |
| Cell lysis occurs during lytic cycle. | No cell lysis occurs in a lysogenic cycle. |
| Following Cycle | |
| The lysogenic cycle follows the lytic cycle. | The lytic cycle follows the lysogenic cycle. |
| Fate of the Host Bacterium | |
| Host bacterium gets destroyed during the lytic cycle. | No destruction of the host bacterium occurs in lysogenic cycle. |
Summary – Lytic vs Lysogenic Cycle of Bacteriophage
Lytic and lysogenic cycles are the two major divisions of bacteriophage reproduction. Lytic cycle involves destruction of the host cell while lysogenic cycles do not. The bacteriophage DNA in lytic cycle presents as a separate unit inside the host cell. But during lysogenic cycle it gets incorporated into the host DNA. This is the difference between lytic and lysogenic cycle of bacteriophage.
Reference :
1.“Lysogenic Cycle.” Lysogenic Cycle – New World Encyclopedia. Available here
Image Courtesy:
1.’6374709127’by xxoverflowed (CC BY 2.0) via Flickr
2.’Phage2’By Suly12 – Own work, (CC BY-SA 3.0) via Commons Wikimedia